import React from "react";

export default class App extends React.Component {
  constructor(props) {
    super(props);
    this.render = this.render.bind(this);
    this.state = {
      items: this.props.items,
      disabled: true
    };
  }

  componentDidMount() {
    this.setState({
      disabled: false
    });
  }

  handleClick() {
    this.setState({
      items: this.state.items.concat("Item " + this.state.items.length)
    });
  }

  render() {
    return (
      <div>
        <button
          onClick={this.handleClick.bind(this)}
          disabled={this.state.disabled}
        >
          Add Item 
        </button>
        <ul>
          {this.state.items.map(function(item, index) {
            return <li key={index}>{item}</li>;
          })}
        </ul>
      </div>
    );
  }
}
